Should be about 750-1000ml,depending on the radiator and the hous diameter, fill in about 500ml,then start the engine and pull the bike in the front up, like a wheely, so the should be the most air out of the system and you can fill up the rest.

Should be about 750-1000ml,depending on the radiator and the hous diameter, fill in about 500ml,then start the engine and pull the bike in the front up, like a wheely, so the should be the most air out of the system and you can fill up the rest.

Thanks. Okay...I have a long way to go, as I think I've only put about 100ml in there right now. I'll leave it overnight and perhaps turn the water pump over with a drill or something similar to work the water through. I'll also try the lifting front up like you've suggested. Thanks.

You can see in the second YouTube clip theres a slight coolant leak coming from the bottom of the pull start area. I'm hoping the seals hydrate and seal, otherwise I'll take it apart.

I assume it's from the shaft seal on the drive pulley? Although I took the pull start cover off and it looks dry? So a bit of a mystery. I'll probably just run it and top up if it's not glaringly obvious where its coming from.

Found the leak, it was the overflow bottle cap. It wasn't 100% sealing and the drip followed down a hose, onto another hose...then dripped to ground near motor. So mystery solved.

In other news:

Well, it goes. But it sucks down low! To be honest its possibly a little less power than I was expecting???

Theres not enough room on my drive to get into power band, and that's when it should liven up a lot. But it has zero low down torque. I'll change the rear sprocket for a 78 tooth, from the 68 tooth that's on it now. That will help.

But I think it's just going to need more room to show its potential, which will be the case on race day. The yard we use is about 100m long so it will be awesome on the straights, just not so great on the corners.

Still...I've enjoyed making it and learnt heaps. Thanks for all the help everyone on here provided.

At what rpm is your clutch currently engaged? It should begin to grip at about 8000rpm, set in warm condition. You also have to make sure that all three arms of the clutch open at the same time. It is also the exhaust is not ideal for this engine, it would have a shorter and thicker exhaust to be mounted.

And with the 14mm carb you will never get the full power of these engine. You can run a 17-19mm carb.

At what rpm is your clutch currently engaged? It should begin to grip at about 8000rpm, set in warm condition. You also have to make sure that all three arms of the clutch open at the same time. It is also the exhaust is not ideal for this engine, it would have a shorter and thicker exhaust to be mounted.

And with the 14mm carb you will never get the full power of these engine. You can run a 17-19mm carb.

Yes, you have to take the engine out and split the cases. The china bearings and seals are junk, get the numbers of them and seal size. I bought SKF bearings and Dupont red Viton shaft seal, after mine failed and destroyed the whole engine.

I went through all the boxes of parts I got when I brought the pocket bikes. There's about 4 complete carburetors in there. Ill measure them up and look for a 19mm one.

I also ordered a 78tooth sprocket and a chain last night and should have it by Tuesday. It takes me about 45 minutes to machine the centre out of the sprocket to fit my rear axle and to redrill the holes to a larger PCD. I think it will make a big difference going from 68 to 78 teeth. I also found a few different clutch sprockets of 6, 7, 8 teeth. I can't recall what is on the front...but if it's more than 6 teeth, I change that out to a 6 tooth to get more lower end torque.

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